[RFC] PPC64 Exporting memory information through /proc/iomem

[Badari Pulavarty]

On Tue, 2007-10-02 at 13:11 -0700, Geoff Levand wrote:
> Hi Badari,
> 
> Badari Pulavarty wrote:
> > Hi Paul & Ben,
> > 
> > I am trying to get hotplug memory remove working on ppc64.
> > In order to verify a given memory region, if its valid or not -
> > current hotplug-memory patches used /proc/iomem. On IA64 and
> > x86-64 /proc/iomem shows all memory regions. 
> > 
> > I am wondering, if its acceptable to do the same on ppc64 also ?
> > Otherwise, we need to add arch-specific hooks in hotplug-remove
> > code to be able to do this.
> 
> 
> It seems the only reasonable place is in /proc/iomem, as the the 
> generic memory hotplug routines put it in there, and if you have
> a ppc64 system that uses add_memory() you will have mem info in
> several places, none of which are complete.  

Well, this information exists in various places (lmb structures
in the kernel), /proc/device-tree for various users. I want to
find out what ppc experts think about making this available through
/proc/iomem also since generic memory hotplug routines expect 
it there.

Other option would be to provide arch-specific call out. Each
arch could decide to implement whatever way they want to verify 
the range.

Thanks,
Badari